Her appearance is just the latest in a long line of politically tinged cameos on TV. With more to come: Jill Biden will pop up on Lifetime's 'Army Wives' in August.

There's a meta moment coming in Monday night's episode of "The Secret Life of the American Teenager" where 19-year-old Bristol Palin talks about being the mother of a toddler. The brief guest appearance came naturally — the acting part, well, that's another matter — because it mirrors her own life.

"It was right up my alley," said Palin, daughter of former Alaska Gov. Sarah Palin. "I was pregnant the same time as the character, Amy, on the show, so I kind of felt like we went through the experience together."

One situation is fact and the other, fiction, of course, with the former spawning a national debate that shook up Sarah Palin's vice presidential campaign and the latter generating no small amount of controversy for Disney-owned ABC Family.

The melding of the two wasn't meant to be a political statement, said the show's creator, Brenda Hampton, but was simply an opportunistic bit of stunt casting.

"The scene was written as a discussion between two teenage moms," Hampton said, "and Bristol Palin is the most famous teen mom in America. It just fit."

The Palin guest spot won't be the only politically tinged cameo on TV this summer, with Jill Biden, wife of Vice President Joe Biden, popping in on Lifetime's "Army Wives" in August. Biden, playing herself, will be featured in an episode about the challenges military families face when a loved one is deployed. Biden has become an emissary for the Obama administration's support for U.S. servicemen and women.

"She's a military mom herself, and so she brings a lot of credibility to the show," said JoAnn Alfano, Lifetime's executive vice president of entertainment. "This feels very organic, not pasted in at all, since the whole series is about the sacrifices that military families make."

Biden worked a 14-hour day and taped a public service announcement that will air at the end of the episode and on the network's website telling viewers how they can support the troops and their families.

Culling from the political landscape isn't new for primetime TV. In fact, there's been an avalanche of Beltway insiders popping up everywhere from "Celebrity Apprentice" (former Illinois Gov. Rod Blagojevich) and "Dancing With the Stars" (former U.S. Rep. Tom DeLay of Texas) to "30 Rock" (former Vice President Al Gore) and WWE's "Monday Night Raw" (Hillary Rodham Clinton, John McCain and Barack Obama). Obama, ever the media darling, got face time on "Idol Gives Back" and at the recent NBA Finals. Sarah Palin is working on her own documentary-style series, a meet-and-greet with residents of Alaska, set to run on TLC.

And these are all outside the usual suspects, such as "The Simpsons," which has featured the voices and animated likenesses of dozens of political leaders; "Saturday Night Live"; and "Today" and "The View," where political wives Laura Bush and Cindy McCain have been guest co-hosts.

Their widespread recognition makes them appealing as TV guests, and producers realize that casting a legislator or wannabe politico will generate free publicity for the show, industry watchers say.

"These appearances are catnip for media attention," said Marty Kaplan, a professor at the USC Annenberg School for Communication & Journalism. "That can get some people to sample the show who might not watch otherwise."

The fusion between politics and entertainment goes back years — Bill Clinton playing sax on "The Arsenio Hall Show" comes to mind — but has intensified recently, Kaplan said, pointing to Arnold Schwarzenegger announcing his California gubernatorial run on "The Tonight Show With Jay Leno." Politicians, some who also double as movie and TV stars, are often as famous today as rock musicians and supermodels.

"There's no distinction between show business celebrities, politicians, CEOs," Kaplan said. "It's all one big issue of People magazine."

For the lawmakers, candidates, their spouses and family members, TV roles can give them a broad forum for touting their pet projects in a context that's more interesting than a dry PSA or a paid ad.

Though Jill Biden will be promoting her real-life cause on "Army Wives," don't look for Bristol Palin to do the same on "Secret Life." There will be no abstinence lecture, Hampton said, even though Palin has become a spokeswoman for teen celibacy. The show, where another teen character just found out she's pregnant and is considering an abortion, features hormonal high schoolers in all their unrestrained glory.

"The show is entertainment — it's not pushing any agenda," Hampton said. "We talk about everything — oral sex, pregnancy, abstinence — and we represent all sides."

There could be a lasting effect, though, from Palin's guest appearance. Hampton said she gleaned so much valuable information from the teen that she's thinking of asking her to become a consultant on the series. Other than a few teen moms she's reached out to during the show's run, Hampton said she doesn't have a go-to person in that demographic who can give her ongoing insight. (Hampton hasn't approached Palin about the role yet).

"Secret Life" chronicles a lot of teen sex, but Palin, whose acting debut has been described as "wooden" and "deer in the headlights," said she felt comfortable as a guest star because it depicts the consequences.

"Having a baby as a teenager isn't glamorous, it isn't fun," she said. "The show's right on track with that."